In [1]}, [2]} it is advocated for the following parameterization of the profile function This ansatz is now supported by light-front holographic QCD [3]}. A similar parameterization
has been proposed in [4]}.
\(f_i^a(x)\,=\,\big (B_i^a - \alpha _i^{\prime }{}^a\ln {x}\big )(1-x)^3 + A_i^a x(1-x)^2\,,\) 
